1. Field of the Invention
The present invention relates to a silicone resin composition used in encapsulation of an optical semiconductor element, a silicone resin sheet obtained by semi-curing the silicone resin composition, an optical semiconductor element device having an encapsulating layer obtained by curing the silicone resin composition, and a method for producing a silicone resin sheet.
2. Description of Related Art
Conventionally, as an encapsulating material for encapsulating an optical semiconductor element such as a light emitting diode (LED), a silicone resin having an excellent transparency has been used.
As such an encapsulating material, for example, a silicone resin composition containing an organopolysiloxane, which contains an alkenyl group, and an organohydrogenpolysiloxane has been known (ref: for example, Japanese Unexamined Patent Publications No. 2000-198930, No 2004-186168, and No. 2008-150437).
The silicone resin composition is usually in a liquid state at room temperature, and an alkenyl group in the organopolysiloxane and a hydrosilyl group in the organohydrogenpolysiloxane are allowed to undergo an addition reaction to be cured by heating in the presence of a platinum catalyst.
In order to encapsulate the optical semiconductor element using the silicone resin composition, for example, a method in which the silicone resin composition fills inside a housing in which the optical semiconductor element is disposed to be cured has been known.
However, in this method, there may be a case where the viscosity or the like of the silicone resin composition in a liquid state changes in accordance with the operating environment, so that it may be difficult to stably fill with the silicone resin composition.
Therefore, for example, a method for fabricating an optical semiconductor encapsulating sheet by heating and drying an encapsulating sheet composition, which contains a silicone resin having a cyclic ether-containing group (to be specific, a glycidyl group, an epoxycyclohexyl group, and an oxetane group) and a thermal curing agent to be reacted with the cyclic ether-containing group, and encapsulating an optical semiconductor element using the optical semiconductor encapsulating sheet has been proposed (ref: for example, Japanese Unexamined Patent Publication No. 2009-84511).